Plants, Organisation and Diseases

Question 1

Give the seven signs of plant disease

Answer 1

Stunted Growth, Spots, Decay, Growths, Malformed Stems and Leaves, Discolouration, Pests

Question 2

Four tests for plant disease identification?

Answer 2

Google or Gardening Manual, DNA Analysis, Monoclonal Antibody Testing Kits, Lab Identification

Question 3

What pathogen causes rose black spot?

Answer 3

Fungus

Question 4

What pathogen causes tobacco mosaic virus

Answer 4

Virus

Question 5

What causes nitrate deficiency (clue in the name)?

Answer 5

Lack of nitrates

Question 6

What causes magnesium ion deficiency?

Answer 6

Lack of magnesium

Question 7

What are the three types of plant defence adaptations?

Answer 7

Physical, Chemical, Mechanical

Question 8

Give three physical defences

Answer 8

Layers of dead cells around the stems (bark), tough waxy cuticle on leaves, cellulose cell walls.

Question 9

Give two chemical defences

Answer 9

Poisons and Antibacterial Chemicals

Question 10

Give three mechanical defences

Answer 10

Leaves that curl or droop when touched, thorns and hairs, mimicry.

Question 11

Give all parts of a plant cell

Answer 11

Nucleus, Chloroplasts, Vacuole, Mitochondria, Cell Wall, Cell Membrane

Question 12

What parts in a plant cell are not in an animal cell?

Answer 12

Vacuole, Chloroplasts, Cell Wall

Question 13

Name the organs in a plant

Answer 13

Stem, roots and leaves

Question 14

Name the parts in a leaf (top to the bottom)

Answer 14

Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll (contains air space), lower epidermis, stomata, guard cell

Question 15

Function of epidermal tissues

Answer 15

Covered in waxy cuticle to reduce water loss via evaporation

Question 16

Function of upper epidermis

Answer 16

Transparent so light can pass through to the palisade layer

Question 17

Function of palisade layer

Answer 17

Contains lots of chloroplasts containing chlorophyll for photosynthesis so the palisade layer is near the top of the leaf to maximise light intake

Question 18

Spongy mesophyll function

Answer 18

Contains air spaces to increase the rate of diffusion of gases by decreasing the diffusion pathway

Question 19

Stomata, guard cells and lower epidermis

Answer 19

Lower epidermis is full of stomata which open and close to allow gas exchange and are controlled by guard cells in response to the environment

Question 20

Translocation

Answer 20

The movement of food substances (mainly sugars) in cell sap forwards and backwards along the plant

Question 21

How are phloem tubes specialised?

Answer 21

Made of columns of elongated living cells with small pores in the end walls to allow for sap to flow through

Question 22

Translocation

Answer 22

Transportation of water and minerals from the roots to the stem and leaves in one direction

Question 23

How are xylem specialised

Answer 23

Made of dead cells joined end to end with no end walls between them and a hole down the middle, they are strengthened with a material called lignin

Question 24

Transpiration stream

Answer 24

The movement of water from the roots through the xylem and out of the leaves is called the transpiration stream

Question 25

What is transpiration?

Answer 25

Evaporation and diffusion of water from a plant’s surface mainly the leaves’ surface

Question 26

Factors affecting the rate of transpiration

Answer 26

Light- brighter means greater rate, temperature- warmer means greater rate, air flow- water particles are attracted to each other so air making water vapour move away from plant means greater rate, humidity- the less humid the bigger the diffusion gradient so the greater the rate

Question 27

How are the stomata specialised

Answer 27

When a plant has a lot of water, guard cells fill with it which makes the stomata open so gases can be exchanged for photosynthesis- when the plant has less water the stomata close to prevent loss of evaporating water- they are sensitive to light and close at night to save water- they are on the bottom because it is cooler so less water is lost